<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'/>
    <title></title>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no'/>
    <script src='../assets/mapbox-gl-dev.js'></script>
    <link href='../assets/mapbox-gl.css' rel='stylesheet'/>
    <style>
        body {
            margin: 0;
            padding: 0;
        }

        #map {
            position: absolute;
            top: 0;
            bottom: 0;
            width: 100%;
        }
    </style>
</head>
<body>

<div id='map'></div>
<script>
    mapboxgl.accessToken = 'pk.eyJ1IjoibWFvcmV5IiwiYSI6ImNqNWhrenIwcDFvbXUyd3I2bTJxYzZ4em8ifQ.KHZIehQuWW9AsMaGtATdwA';
    var map = new mapboxgl.Map({
        container: 'map',
        style: 'mapbox://styles/mapbox/streets-v9',
        center: [0, 0],
        zoom: 2
    });

    var radius = 20;

    function pointOnCircle(angle) {
        return {
            "type": "Point",
            "coordinates": [
                // Math.cos(angle + 1) * radius,
                angle,
                Math.sin(angle - 1) * radius
            ]
        };
    }

    map.on('load', function () {
        // Add a source and layer displaying a point which will be animated in a circle.
        map.addSource('point', {
            "type": "geojson",
            "data": pointOnCircle(0)
        });

        map.addLayer({
            "id": "point",
            "source": "point",
            "type": "circle",
            "paint": {
                "circle-radius": 10,
                "circle-color": "#007cbf"
            }
        });

        function animateMarker(timestamp) {
            // Update the data to a new position based on the animation timestamp. The
            // divisor in the expression `timestamp / 1000` controls the animation speed.
            map.getSource('point').setData(pointOnCircle(timestamp / 1000));
            map.setPaintProperty(map.getLayer('point').id, 'circle-radius', Math.random() * 20 + 1);
            map.setPaintProperty(map.getLayer('point').id, 'circle-color', '#' + parseInt(Math.random() * 9) + parseInt(Math.random() * 9) + parseInt(Math.random() * 9));
            // map.getLayer('point').setPaintProperty('circle-radius', Math.random() * 20 + 1);
            // Request the next frame of the animation.
            requestAnimationFrame(animateMarker);
        }

        // Start the animation.
        animateMarker(0);
    });
</script>

</body>
</html>